Shovel

ABSTRACT

A shovel may include a lower traveling body; an upper turning body turnably mounted on the lower traveling body; and a control device disposed in the upper turning body, wherein the control device includes a processor, and a memory storing a computer-readable program, which when executed, causes the processor to execute a process including recognizing a position subject to a backfilling operation, and generating a target position relating to the backfilling operation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application filed under 35 U.S.C. 111(a) claiming benefit under 35 U.S.C. 120 and 365(c) of PCT InternationalApplication No. PCT/JP2022/012421, filed on Mar. 17, 2022, anddesignating the U.S., which claims priority to Japanese PatentApplication No. 2021-044182 filed on Mar. 17, 2021. The entire contentsof the foregoing applications are incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates to a shovel.

Description of Related Art

Hydraulic excavators known in the related art are typically equippedwith a semi-autonomous excavation control system. The excavation controlsystem is configured to perform an autonomous boom-raising turningoperation when a predetermined condition is met.

SUMMARY

According to an aspect of the present disclosure, a shovel includes alower traveling body; an upper turning body turnably mounted on thelower traveling body; and a control device disposed in the upper turningbody, wherein the control device includes a processor, and a memorystoring a computer-readable program, which when executed, causes theprocessor to execute a process including recognizing a position subjectto a backfilling operation, and generating a target position relating tothe backfilling operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view illustrating a shovel according to an embodimentof the present disclosure.

FIG. 1B is a top view illustrating the shovel according to theembodiment of the present disclosure.

FIG. 2 is a diagram illustrating an example of a configuration of ahydraulic system mounted on a shovel.

FIG. 3A is a diagram illustrating a part of the hydraulic systemrelating to an operation of an arm cylinder.

FIG. 3B is a diagram illustrating a part of the hydraulic systemrelating to an operation of a turning hydraulic motor.

FIG. 3C is a diagram illustrating a part of the hydraulic systemrelating to an operation of a boom cylinder.

FIG. 3D is a diagram illustrating a part of the hydraulic systemrelating to an operation of a bucket cylinder.

FIG. 4 is a functional block diagram illustrating a controller.

FIG. 5 is a block diagram illustrating an autonomous control function.

FIG. 6 is a block diagram illustrating an autonomous control function.

FIG. 7A is a top view illustrating the shovel performing a backfillingoperation.

FIG. 7B is a top view illustrating the shovel performing a backfillingoperation.

FIG. 7C is a top view illustrating the shovel performing a backfillingoperation.

FIG. 8A is a cross-sectional view illustrating a hole subjected to abackfilling operation.

FIG. 8B is a cross-sectional view illustrating the hole subjected to abackfilling operation.

FIG. 8C is a cross-sectional view illustrating the hole subjected to abackfilling operation.

FIG. 9A is a cross-sectional view illustrating the backfilled hole.

FIG. 9B is a cross-sectional view illustrating the backfilled hole.

FIG. 10A is a top view illustrating the shovel performing anotherbackfilling operation.

FIG. 10B is a cross-sectional view illustrating a hole subject toanother backfilling operation.

FIG. 11 is a top view illustrating the shovel performing still anotherbackfilling operation.

FIG. 12A is a cross-sectional view of a hole subjected to yet anotherbackfilling operation.

FIG. 12B is a cross-sectional view illustrating the hole subject to yetanother backfilling operation.

FIG. 12C is a cross-sectional view illustrating the hole subject to yetanother backfilling operation.

EMBODIMENT OF THE INVENTION

According to an embodiment of the present disclosure, a techniquecapable of enhancing the efficiency of the backfilling operation can beprovided.

First, a shovel 100 as an excavator according to an embodiment of thepresent disclosure will be described with reference to FIGS. 1A and 1B.FIG. 1A is a side view illustrating the shovel 100, and FIG. 1B is a topview illustrating the shovel 100.

In the present embodiment, a lower traveling body 1 of the shovel 100includes a crawler 1C. The crawler 1C is driven by a traveling hydraulicmotor 2M mounted on the lower traveling body 1. Specifically, thecrawler 1C includes a left crawler 1CL and a right crawler 1CR. The leftcrawler 1CL is driven by a left traveling hydraulic motor 2ML, and theright crawler 1CR is driven by a right traveling hydraulic motor 2MR.

An upper turning body 3 is mounted on the lower traveling body 1 so asto be able to turn through a turning mechanism 2. The turning mechanism2 is driven by a turning hydraulic motor 2A mounted on the upper turningbody 3. However, the turning hydraulic motor 2A may be a turningelectric generator as an electric actuator.

A boom 4 is attached to the upper turning body 3. An arm 5 is attachedto the tip of the boom 4, and a bucket 6 as an end attachment isattached to the tip of the arm 5. The boom 4, the arm 5, and the bucket6 constitute an excavation attachment AT which is an example of anattachment. The boom 4 is driven by a boom cylinder 7, the arm 5 isdriven by an arm cylinder 8, and the bucket 6 is driven by a bucketcylinder 9.

The boom 4 is supported in a vertically rotatable manner with respect tothe upper turning body 3. A boom angle sensor S1 is attached to the boom4. The boom angle sensor S1 can detect a boom angle β₁ which is arotation angle of the boom 4. The boom angle β₁ is, for example, arising angle from a state in which the boom 4 is lowered most.Therefore, the boom angle β₁ is maximum when the boom 4 is raised most.

The arm 5 is rotatably supported with respect to the boom 4. An armangle sensor S2 is attached to the arm 5. The arm angle sensor S2 candetect an arm angle β₂ which is a rotation angle of the arm 5. The armangle β₂ is, for example, an opening angle from the state where the arm5 is most closed. Therefore, the arm angle β₂ is maximum when the arm 5is most opened.

The bucket 6 is rotatably supported with respect to the arm 5. A bucketangle sensor S3 is attached to the bucket 6. The bucket angle sensor S3can detect a bucket angle β₃ which is a rotation angle of the bucket 6.The bucket angle β₃ is an opening angle from the state where the bucket6 is closed most. Therefore, the bucket angle β₃ is maximum when thebucket 6 is opened most.

In the embodiment illustrated in FIGS. 1A and 1B, the boom angle sensorS1, the arm angle sensor S2, and the bucket angle sensor S3 each includea combination of an acceleration sensor and a gyro sensor. However, theboom angle sensor S1, the arm angle sensor S2, and the bucket anglesensor S3 may each be configured to include an acceleration sensoralone. The boom angle sensor S1 may be a stroke sensor attached to theboom cylinder 7, or may be a rotary encoder, a potentiometer, or aninertial measurement device. The same applies to the arm angle sensor S2and the bucket angle sensor S3.

The upper turning body 3 is provided with a cabin as a driver'scompartment, and one or a plurality of power sources are mounted on theupper turning body 3. In the present embodiment, the upper turning body3 is mounted with an engine 11 as a power source. The upper turning body3 is mounted with an object detection device 70, an imaging device abody inclination sensor S4, a turning angular velocity sensor S5, andthe like. An operation device 26, a controller a display device D1, anda sound output device D2 are provided inside the cabin 10. In thisspecification, for convenience, the side to which the excavationattachment AT is attached is designated as a front side, and the side towhich a counterweight is attached is designated as a back side.

The object detection device 70 is configured to detect an objectexisting around the shovel 100. The object may be, for example, aperson, an animal, a vehicle, a construction machine, a structure, awall, a fence, or a hole. The object detection device 70 may be, forexample, an ultrasonic sensor, a millimeter-wave radar, a stereo camera,a LIDAR, a range image sensor, or an infrared sensor. In the presentembodiment, the object detection device 70 includes a front sensor 70Fattached to a front end of an upper surface of the cabin 10, a rearsensor 70B attached to a rear end of an upper surface of the upperturning body 3, a left sensor attached to a left end of the uppersurface of the upper turning body 3, and a right sensor 70R attached toa right end of the upper surface of the upper turning body 3. Eachsensor includes a LIDAR.

The object detection device 70 may be independent of the shovel 100. Inthis case, the controller 30 may acquire an image of a work site aroundthe shovel output by the object detection device 70 through acommunication device. Specifically, the object detection device 70 maybe attached to a multicopter for aerial photography, or may be attachedto a steel tower, an electric pole, or the like installed at the worksite. Then, the controller 30 may acquire information on the work sitebased on the captured image viewed from above.

The object detection device 70 may be configured to detect apredetermined object within a predetermined area set around the shovel100. That is, the object detection device 70 may be configured toidentify the type of object. For example, the object detection device 70may be configured to distinguish between a person and an object otherthan the person (dump trucks, utility poles, fences, holes, or landformssuch as sediment piles, etc.). The object detection device 70 may beconfigured to calculate a distance from the object detection device 70or the shovel 100 to a recognized object. Thus, when the object to berecognized is a landform, the object detection device 70 can recognize adistance from the object detection device 70 or the shovel 100 to eachmeasuring position of the landform to be measured, and can alsorecognize an uneven shape of the landform to be measured. When a holeexists in the landform to be measured, the object detection device 70can also recognize a shape (area, depth, etc.) and a position of thehole.

The imaging device 80 is configured to image an area around the shovel100. In the present embodiment, the imaging device 80 includes a rearcamera 80B attached to the upper rear end of the upper turning body 3, afront camera 80F attached to the upper front end of the cabin 10, a leftcamera 80L attached to the upper left end of the upper turning body 3,and a right camera 80R attached to the upper right end of the upperturning body 3.

The rear camera 80B is disposed adjacent to the rear sensor 70B, thefront camera 80F is disposed adjacent to the front sensor 70F, the leftcamera 80L is disposed adjacent to the left sensor 70L, and the rightcamera 80R is disposed adjacent to the right sensor 70R.

The image captured by the imaging device 80 is displayed on the displaydevice D1. The imaging device 80 may be configured to display aviewpoint conversion image such as an overhead view image on the displaydevice D1. The overhead view image is generated by combining imagesoutput by the rear camera 80B, the left camera 80L, and the right camera80R, for example.

The imaging device 80 may be used as the object detection device 70. Inthis case, the object detection device 70 may be omitted.

The body inclination sensor S4 is configured to detect an inclination ofthe upper turning body 3 with respect to a predetermined plane. In thepresent embodiment, the body inclination sensor S4 is an accelerationsensor configured to detect an inclination angle of the upper turningbody 3 around the longitudinal axis and an inclination angle around thelateral axis, with respect to a virtual horizontal plane. Thelongitudinal (front-back) axis and the lateral (left-right) axis of theupper turning body 3 are, for example, orthogonal to each other, andpass through the center point of the shovel, which is one point on theturning axis of the shovel 100.

The turning angular velocity sensor S5 is configured to detect theturning angular velocity of the upper turning body 3. In the presentembodiment, the turning angular velocity sensor S5 is a gyro sensor. Theturning angular velocity sensor S5 may be a resolver or a rotaryencoder. The turning angular velocity sensor S5 may detect rotationalvelocity. The rotational velocity may be calculated from the turningangular velocity.

Hereinafter, the boom angle sensor S1, the arm angle sensor S2, thebucket angle sensor S3, the body inclination sensor S4, and the turningangular velocity sensor S5 are each also referred to as an attitudedetection device.

The display device D1 is a device for displaying information. The soundoutput device D2 is a device for outputting sound. The operation device26 is a device used by an operator for operating an actuator.

The controller 30 is a control device configured to control the shovel100. In the present embodiment, the controller 30 includes a computerhaving a CPU, a volatile storage device, a nonvolatile storage device,and the like. The controller 30 reads a program corresponding to eachfunction from the nonvolatile storage device, loads the program into thevolatile storage device, and causes the CPU to execute a correspondingprocess. Each function includes, for example, a machine guidancefunction that guides a manual operation of the shovel 100 by theoperator, and a machine control function that automatically supports themanual operation of the shovel 100 by the operator.

Next, an example of a configuration of a hydraulic system mounted on theshovel 100 will be described with reference to FIG. 2 . FIG. 2 is adiagram illustrating the example of the configuration of a hydraulicsystem mounted on the shovel 100. FIG. 2 illustrates a mechanical powertransmission line, a hydraulic fluid line, a pilot line, and anelectrical control line by double, solid, dashed, and dotted lines,respectively.

The hydraulic system of the shovel 100 mainly includes an engine 11, aregulator 13, a main pump 14, a pilot pump 15, a control valve unit 17,an operation device 26, a discharge pressure sensor 28, an operationpressure sensor 29, a controller 30, and the like.

In FIG. 2 , the hydraulic system circulates hydraulic fluid from themain pump 14 driven by the engine 11 through a center bypass conduitline 40 or a parallel conduit line 42 to a hydraulic fluid tank.

The engine 11 is a driving source for the shovel 100. In the presentembodiment, the engine 11 is, for example, a diesel engine that operatesto maintain a predetermined speed. An output shaft of the engine 11 iscoupled to respective input shafts of the main pump 14 and the pilotpump 15.

The main pump 14 is configured to supply hydraulic fluid to the controlvalve unit 17 via the hydraulic fluid line. In the present embodiment,the main pump 14 is a swashplate type variable displacement hydraulicpump.

The regulator 13 is configured to control a discharge amount (push-offvolume volume) of the main pump 14. In the present embodiment, theregulator 13 controls the discharge amount (push-off volume volume) ofthe main pump 14 by adjusting a swash plate tilt angle of the main pump14 in response to a control instruction from the controller 30.

The pilot pump 15 is configured to supply hydraulic fluid to hydrauliccontrol device including the operation device 26 via a pilot line. Inthe present embodiment, the pilot pump 15 is a fixed displacementhydraulic pump. However, the pilot pump 15 may be omitted. In this case,the function of the pilot pump 15 may be implemented by the main pump14. That is, the main pump 14 may have, apart from a function ofsupplying hydraulic fluid to the control valve unit 17, a function ofsupplying hydraulic fluid to the operation device 26 or the like afterlowering the pressure of the hydraulic fluid by a restrictor, or thelike.

The control valve unit 17 is configured to control a flow of hydraulicfluid in the hydraulic system. In the present embodiment, the controlvalve unit 17 includes control valves 171 to 176. The control valve 175includes a control valve 175L and a control valve 175R, and the controlvalve 176 includes a control valve 176L and a control valve 176R. Thecontrol valve unit 17 can selectively supply hydraulic fluid dischargedby the main pump 14 to one or more hydraulic actuators through thecontrol valves 171 to 176. The control valves 171 to 176 control flowrates of hydraulic fluid flowing from the main pump 14 to the hydraulicactuators and flow rates of hydraulic fluid flowing from the hydraulicactuators to the hydraulic fluid tank. The hydraulic actuators include aboom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a lefttraveling hydraulic motor 2ML, a right traveling hydraulic motor 2MR,and a turning hydraulic motor 2A.

The operation device 26 is a device used by an operator for operating anactuator. The actuator includes at least one of a hydraulic actuator andan electric actuator. In the present embodiment, the operation device 26supplies hydraulic fluid delivered by the pilot pump 15 to a pilot portof the corresponding control valve in the control valve unit 17 via thepilot line. The pressure of the hydraulic fluid supplied to each of thepilot ports (pilot pressure) is a pressure corresponding to an operatingdirection and an operating amount of a lever or a pedal (notillustrated) of the operation device 26 with respect to a correspondingone of the hydraulic actuators; however, the operation device 26 may bean electric operation device rather than the hydraulic operation deviceas described above. In this case, the control valve in the control valveunit 17 may be an electromagnetic spool valve.

The discharge pressure sensor 28 is configured to detect a dischargepressure of the main pump 14. In the present embodiment, the dischargepressure sensor 28 outputs a detected value to the controller 30.

The operation pressure sensor 29 is configured to detect an operation ofthe operation device 26 performed by the operator. In the presentembodiment, the operation pressure sensor 29 detects the operationdirection and the operation amount of the operation device 26corresponding to each actuator in the form of pressure (operationpressure), and outputs the detected value to the controller 30 asoperation data. The operation content of the operation device 26 may bedetected using other sensors other than the operation pressure sensor.

The main pump 14 includes a left main pump 14L and a right main pump14R. The left main pump 14L is configured to circulate hydraulic fluidto the hydraulic fluid tank via a left center bypass conduit line 40L ora left parallel conduit line 42L. The right main pump 14R is configuredto circulate hydraulic fluid to the hydraulic fluid tank via a rightcenter bypass conduit line 40R or a right parallel conduit line 42R.

The left center bypass conduit line 40L is a hydraulic fluid linepassing through the control valves 171, 173, 175L, and 176L locatedwithin the control valve unit 17. The right center bypass conduit line40R is a hydraulic fluid line passing through the control valves 172,174, 175R, and 176R located within the control valve unit 17.

The control valve 171 is a spool valve that supplies hydraulic fluiddischarged by the left main pump 14L to the left traveling hydraulicmotor 2ML, and switches a flow of hydraulic fluid to discharge thehydraulic fluid discharged by the left traveling hydraulic motor 2ML tothe hydraulic fluid tank.

The control valve 172 is a spool valve that supplies the hydraulic fluiddischarged by the right main pump 14R to the right traveling hydraulicmotor 2MR, and switches the flow of hydraulic fluid to discharge thehydraulic fluid discharged by the right traveling hydraulic motor 2MR tothe hydraulic fluid tank.

The control valve 173 is a spool valve that supplies the hydraulic fluiddischarged by the left main pump 14L to the turning hydraulic motor 2A,and switches the flow of hydraulic fluid to discharge the hydraulicfluid discharged by the turning hydraulic motor 2A to the hydraulicfluid tank.

The control valve 174 is a spool valve that supplies the hydraulic fluiddischarged by the right main pump 14R to the bucket cylinder 9, andswitches the flow of hydraulic fluid to discharge the hydraulic fluid inthe bucket cylinder 9 to the hydraulic fluid tank.

The control valve 175L is a spool valve that switches the flow of thehydraulic fluid to supply the hydraulic fluid discharged from the leftmain pump 14L to the boom cylinder 7. The control valve 175R is a spoolvalve that switches the flow of the hydraulic fluid to supply thehydraulic fluid discharged from the right main pump 14R to the boomcylinder 7, and discharges the hydraulic fluid in the boom cylinder 7 tothe hydraulic fluid tank.

The control valve 176L is a spool valve that switches the flow of thehydraulic fluid to supply the hydraulic fluid discharged from the leftmain pump 14L to the arm cylinder 8, and discharges the hydraulic fluidin the arm cylinder 8 to the hydraulic fluid tank.

The control valve 176R is a spool valve that switches the flow of thehydraulic fluid to supply the hydraulic fluid discharged from the rightmain pump 14R to the arm cylinder 8, and discharges the hydraulic fluidin the arm cylinder 8 to the hydraulic fluid tank.

The left parallel conduit line 42L is a hydraulic fluid line parallel tothe left center bypass conduit line 40L. The left parallel conduit line42L may supply hydraulic fluid to a further downstream control valvewhen hydraulic fluid flowing through the left center bypass conduit lineis restricted or blocked by either the control valves 171, 173, or 175L.The right parallel conduit line 42R is a hydraulic fluid line parallelto the right center bypass conduit line 40R. The right parallel conduitline 42R may supply hydraulic fluid to a further downstream controlvalve when hydraulic fluid flowing through the right center bypassconduit line 40R is restricted or blocked by either the control valves172, 174, or 175R.

The regulator 13 includes a left regulator 13L and a right regulator13R. The left regulator 13L controls the discharge amount of the leftmain pump 14L by adjusting a swash plate inclination angle of the leftmain pump 14L according to the discharge pressure of the left main pump14L. Specifically, the left regulator 13L reduces the discharge amountby adjusting the swash plate inclination angle of the left main pump 14Laccording to an increase in the discharge pressure of the left main pump14L, for example. The same applies to the right regulator 13R. This isbecause the absorbed power (e.g., absorbed horsepower) of the main pump14, which is represented by the product of the discharge pressure andthe discharge amount, does not exceed the output power (e.g., outputhorsepower) of the engine 11.

The operation device 26 includes a left operation lever 26L, a rightoperation lever 26R, and a traveling lever 26D. The traveling lever 26Dincludes a left traveling lever 26DL and a right traveling lever 26DR.

The left operation lever 26L is one of the operation levers, and is usedfor turning operation and operation of the arm 5. When the leftoperation lever 26L is operated in the front-back direction, thehydraulic fluid discharged from the pilot pump 15 is utilized to operatethe control pressure corresponding to the lever operation amount on thepilot port of the control valve 176. When the left operation lever 26Lis operated in the left-right direction, the hydraulic fluid dischargedfrom the pilot pump is utilized to operate the control pressurecorresponding to the lever operation amount on the pilot port of thecontrol valve 173.

Specifically, when the left operation lever 26L is operated in the armclosing direction, the hydraulic fluid is introduced into the rightpilot port of the control valve 176L, and the hydraulic fluid isintroduced into the left pilot port of the control valve 176R. When theleft operation lever 26L is operated in an arm opening direction, thehydraulic fluid is introduced into the left pilot port of the controlvalve 176L, and the hydraulic fluid is introduced into the right pilotport of the control valve 176R. When the left operation lever 26L isoperated in a left turning direction, the hydraulic fluid is introducedinto the left pilot port of the control valve 173, and when the leftoperation lever 26L is operated in a right turning direction, thehydraulic fluid is introduced into the right pilot port of the controlvalve 173.

The right operation lever 26R is one of the operation levers, and isused for operation of the boom 4 and operation of the bucket 6. When theright operation lever 26R is operated in the front-back direction, thehydraulic fluid discharged from the pilot pump 15 is utilized to operatethe control pressure corresponding to the lever operation amount on thepilot port of the control valve 175. When the right operation lever 26Ris operated in the left-right direction, the hydraulic fluid dischargedfrom the pilot pump is utilized to operate the control pressurecorresponding to the lever operation amount on the pilot port of thecontrol valve 174.

Specifically, when the right operation lever 26R is operated in the boomlowering direction, the hydraulic fluid is introduced into the rightpilot port of the control valve 175R. When the right operation lever 26Ris operated in the boom raising direction, the hydraulic fluid isintroduced into the right pilot port of the control valve 175L, and thehydraulic fluid is introduced into the left pilot port of the controlvalve 175R. When the right operation lever 26R is operated in the bucketclosing direction, the hydraulic fluid is introduced into the left pilotport of the control valve 174, and when the right operation lever 26R isoperated in the bucket opening direction, the hydraulic fluid isintroduced into the right pilot port of the control valve 174.

The traveling lever 26D is used to operate the crawler 1C. Specifically,the left traveling lever 26DL is used to operate the left crawler 1CL.The left traveling lever 26DL may be configured to be interlocked withthe left traveling pedal. When the left traveling lever 26DL is operatedin the front-back direction, the hydraulic fluid discharged from thepilot pump 15 is utilized to operate the control pressure correspondingto the lever operation amount on the pilot port of the control valve171. The right traveling lever 26DR is used to operate the right crawler1CR. The right traveling lever 26DR may be configured to be interlockedwith the right traveling pedal. When operated in the front-backdirection, the right traveling lever 26DR utilizes hydraulic fluiddischarged from the pilot pump 15 to exert a control pressurecorresponding to the lever operation amount on the pilot port of thecontrol valve 172.

The discharge pressure sensor 28 includes a discharge pressure sensor28L and a discharge pressure sensor 28R. The discharge pressure sensor28L detects the discharge pressure of the left main pump 14L and outputsthe detected value to the controller 30. The same applies to thedischarge pressure sensor 28R.

The operation pressure sensor 29 includes operation pressure sensors29LA, 29LB, 29RA, 29RB, 29DL, and 29DR. The operation pressure sensor29LA detects the contents of the operator's operation of the leftoperation lever 26L in the front-back direction in the form of pressure,and outputs the detected value to the controller 30. The contents of theoperation are, for example, the lever operation direction and the leveroperation amount (lever operation angle).

Similarly, the operation pressure sensor 29LB detects the contents ofthe operator's operation in the left-right direction with respect to theleft operation lever 26L in the form of pressure, and outputs thedetected value to the controller 30. The operation pressure sensor 29RAdetects the contents of the operator's operation in the front-backdirection with respect to the right operation lever 26R in the form ofpressure, and outputs the detected value to the controller 30. Theoperation pressure sensor 29RB detects the contents of the operator'soperation in the left-right direction with respect to the rightoperation lever 26R in the form of pressure, and outputs the detectedvalue to the controller 30. The operation pressure sensor 29DL detectsthe contents of the operator's operation in the front-back directionwith respect to the left traveling lever 26DL in the form of pressure,and outputs the detected value to the controller 30. The operationpressure sensor 29DR detects the contents of the operator's operation inthe front-back direction with respect to the right traveling lever 26DRin the form of pressure, and outputs the detected value to thecontroller 30.

The controller 30 receives the output of the operation pressure sensor29 and, if necessary, outputs a control instruction to the regulator 13to change the discharge amount of the main pump 14. The controller 30receives the output of the control pressure sensor 19 provided upstreamof the restrictor 18 and, if necessary, outputs a control instruction tothe regulator 13 to change the discharge amount of the main pump 14. Therestrictor 18 includes a left restrictor 18L and a right restrictor 18R,and the control pressure sensor 19 includes a left control pressuresensor 19L and a right control pressure sensor 19R. In the left centerbypass conduit line 40L, a left restrictor 18L is disposed between thecontrol valve 176L located at the most downstream and the hydraulicfluid tank. Therefore, the flow of hydraulic fluid discharged from theleft main pump 14L is restricted by the left restrictor 18L. The leftrestrictor 18L generates a control pressure for controlling the leftregulator 13L. The left control pressure sensor 19L is a sensorconfigured to detect the control pressure and output the detected valueto the controller 30. The controller 30 controls the discharge amount ofthe left main pump 14L by adjusting the swash plate inclination angle ofthe left main pump 14L according to the control pressure. The controller30 decreases the discharge amount of the left main pump 14L as thecontrol pressure is larger, and increases the discharge amount of theleft main pump 14L as the control pressure is smaller. The dischargeamount of the right main pump 14R is similarly controlled.

Specifically, as illustrated in FIG. 2 , when the hydraulic actuators inthe shovel 100 are in a standby state in which none of the hydraulicactuators are operated, the hydraulic fluid discharged from the leftmain pump 14L passes through the left center bypass conduit line 40L tothe left restrictor 18L. The flow of hydraulic fluid discharged from theleft main pump 14L increases the control pressure generated upstream ofthe left restrictor 18L. As a result, the controller 30 reduces thedischarge amount of the left main pump 14L to the minimum allowabledischarge amount, and prevents the pressure loss (pumping loss) when thehydraulic fluid discharged from the left main pump 14L passes throughthe left center bypass conduit line 40L. On the other hand, when anyhydraulic actuator is operated, the hydraulic fluid discharged from theleft main pump 14L flows into the hydraulic actuator to be operated viathe control valve corresponding to the hydraulic actuator to beoperated. Thus, the amount reaching the left restrictor 18L of the flowof the hydraulic fluid discharged from the left main pump 14L is reducedor eliminated, which reduces the control pressure generated upstream ofthe left restrictor 18L. As a result, the controller 30 increases thedischarge amount of the left main pump 14L, allows sufficient hydraulicfluid to flow into the hydraulic actuator to be operated, and ensuresthe operation of the hydraulic actuator to be operated. The controller30 also controls the discharge amount of the right main pump 14R in thesame manner.

With the above-described configuration, the hydraulic system of FIG. 2can prevent wasteful energy consumption with respect to the main pump 14in the standby state. The wasteful energy consumption includes pumpinglosses caused by hydraulic fluid discharged by the main pump 14 in thecenter bypass conduit line 40. In addition, the hydraulic system of FIG.2 can reliably supply necessary and sufficient hydraulic fluid from themain pump 14 to the hydraulic actuator to be operated when the hydraulicactuator is operated.

Next, with reference to FIGS. 3A to 3D, a configuration for operatingthe actuator by the machine control function of the controller 30 willbe described. FIGS. 3A to 3D are views in which a part of the hydraulicsystem is extracted. Specifically, FIG. 3A is a view in which a part ofthe hydraulic system relating to the operation of the arm cylinder 8 isextracted, and FIG. 3B is a view in which a part of the hydraulic systemrelating to the operation of the boom cylinder 7 is extracted. FIG. 3Cis a view in which a part of the hydraulic system relating to theoperation of the bucket cylinder 9 is extracted, and FIG. 3D is a viewin which a part of the hydraulic system relating to the operation of theturning hydraulic motor 2A is extracted.

As illustrated in FIGS. 3A to 3D, the hydraulic system includes aproportional valve 31. The proportional valve 31 includes proportionalvalves 31AL to 31DL, and proportional valves 31AR to 31DR.

The proportional valve 31 functions as a control valve for machinecontrol. The proportional valve 31 is disposed in a conduit lineconnecting the pilot pump 15 and a pilot port of a corresponding controlvalve in the control valve unit 17, and is configured to change the flowpath area of that conduit line. In the present embodiment, theproportional valve 31 operates in response to a control instructionoutput by the controller 30. Therefore, the controller 30 can supplyhydraulic fluid delivered by the pilot pump 15 to the pilot port of thecorresponding control valve in the control valve unit 17 via theproportional valve 31, independent of the operator's operation of theoperation device 26. The controller 30 can then apply the pilot pressuregenerated by the proportional valve 31 to the pilot port of thecorresponding control valve.

With this configuration, the controller 30 can operate the hydraulicactuator corresponding to the specific operation device 26 even when nooperation is performed on the specific operation device 26. Thecontroller 30 can forcibly stop operation of hydraulic actuatorscorresponding to the specific operation device 26 even when an operationis performed on the specific operation device 26.

For example, as illustrated in FIG. 3A, the left operation lever 26L isused to operate the arm 5. Specifically, the left operation lever 26Luses hydraulic fluid discharged from the pilot pump 15 to act on thepilot port of the control valve 176 with pilot pressure corresponding tothe operation in the front-back direction. More specifically, the leftoperation lever 26L acts on the right pilot port of the control valve176L and the left pilot port of the control valve 176R with pilotpressures corresponding to the operation amounts when operated in thearm closing direction (backward direction). Further, the left operationlever 26L acts on the left pilot port of the control valve 176L and theright pilot port of the control valve 176R with pilot pressurescorresponding to the operation amounts when operated in the arm openingdirection (forward direction).

The left operation lever 26L is provided with a switch NS. In thepresent embodiment, the switch NS is a push button switch provided atthe tip of the left operation lever 26L. The operator can operate theleft operation lever 26L while pressing the switch NS. The switch NS maybe disposed on the right operation lever 26R or at another position inthe cabin 10.

The operation pressure sensor 29LA detects the contents of the operationin the front-back direction with respect to the left operation lever 26Lby the operator, and outputs the detected value to the controller 30.

A proportional valve 31AL operates in response to a control instruction(current instruction) output by the controller 30. The pilot pressure ofthe hydraulic fluid introduced from the pilot pump 15 to the right pilotport of the control valve 176L and the left pilot port of the controlvalve 176R is adjusted via the proportional valve 31AL. A proportionalvalve 31AR operates in response to a control instruction (currentinstruction) output by the controller 30. Then, the pilot pressure ofthe hydraulic fluid introduced into the left pilot port of the controlvalve 176L and the right pilot port of the control valve 176R isadjusted from the pilot pump 15 via the proportional valve 31AR. Theproportional valve 31AL can adjust the pilot pressure so that thecontrol valve 176L and the control valve 176R can be stopped at anyvalve position. Similarly, the proportional valve 31AR can adjust thepilot pressure so that the control valve 176L and the control valve 176Rcan be stopped at any valve position.

With this configuration, the controller 30 can supply the hydraulicfluid discharged from the pilot pump 15 to the right pilot port of thecontrol valve 176L and the left pilot port of the control valve 176R viathe proportional valve 31AL in response to the operator's arm closingoperation. The controller 30 can also supply the hydraulic fluiddischarged from the pilot pump 15 to the right pilot port of the controlvalve 176L and the left pilot port of the control valve 176R via theproportional valve 31AL, independently of the operator's arm closingoperation. That is, the controller 30 can close the arm 5 in response tothe operator's arm closing operation or independently of the operator'sarm closing operation.

In response to the operator's arm opening operation, the controller 30can supply the hydraulic fluid discharged from the pilot pump 15 to theleft pilot port of the control valve 176L and the right pilot port ofthe control valve 176R via the proportional valve 31AR. Regardless ofthe operator's arm opening operation, the controller 30 can supply thehydraulic fluid discharged from the pilot pump 15 to the left pilot portof the control valve 176L and the right pilot port of the control valve176R via the proportional valve 31AR. That is, the controller 30 canopen the arm 5 in response to the operator's arm opening operation orindependently of the operator's arm opening operation.

With this configuration, the controller 30 can reduce the pilot pressureacting on the closed pilot port of the control valve 176 (the left pilotport of the control valve 176L and the right pilot port of the controlvalve 176R), and forcibly stop the closing operation of the arm 5, ifnecessary, even when the operator is performing the arm closingoperation. The same applies to the case of forcibly stopping the openingoperation of the arm 5 when the operator is performing the arm openingoperation.

Alternatively, the controller 30 may, if necessary, control theproportional valve 31AR, increase the pilot pressure acting on the openpilot port of the control valve 176 (the right pilot port of the controlvalve 176L and the left pilot port of the control valve 176R) oppositethe closed pilot port of the control valve 176, and forcibly return thecontrol valve 176 to the neutral position to forcibly stop the closingoperation of the arm 5, even when an operator is performing an armclosing operation. The same applies to a case of forcibly stopping theopening operation of the arm 5 when an operator is performing an armopening operation.

The same applies to a case of forcibly stopping the operation of theboom 4 when a boom raising operation or a boom lowering operation isperformed by the operator, a case of forcibly stopping the operation ofthe bucket 6 when a bucket closing operation or a bucket openingoperation is performed by the operator, and a case of forcibly stoppingthe turning operation of the upper turning body 3 when the turningoperation is performed by the operator, although the illustration withreference to FIGS. 3B to 3D below is omitted. The same applies to a caseof forcibly stopping a traveling operation of the lower traveling body 1when the traveling operation is performed by the operator.

As illustrated in FIG. 3B, the right operation lever 26R is used tooperate the boom 4. Specifically, the right operation lever 26R utilizesthe hydraulic fluid discharged from the pilot pump 15, and causes thepilot pressure corresponding to the operation in the front-backdirection to act on the pilot port of the control valve 175. Morespecifically, the right operation lever 26R causes the pilot pressurecorresponding to the operation amount to act on the right pilot port ofthe control valve 175L and the left pilot port of the control valve 175Rwhen operated in the boom raising direction (backward direction). Whenthe right operation lever 26R is operated in the boom lowering direction(forward direction), the pilot pressure corresponding to the operationamount acts on the right pilot port of the control valve 175R.

The operation pressure sensor 29RA detects the contents of the operationin the front-back direction of the right operation lever 26R by theoperator, and outputs the detected value to the controller 30.

A proportional valve 31BL operates in response to a control instruction(current instruction) output by the controller 30. Then, the pilotpressure by the hydraulic fluid introduced into the right pilot port ofthe control valve 175L and the left pilot port of the control valve 175Ris adjusted from the pilot pump 15 via the proportional valve 31BL. Aproportional valve 31BR operates in response to a control instruction(current instruction) output by the controller 30. Then, the pilotpressure due to hydraulic fluid introduced from the pilot pump 15 to theright pilot port of the control valve 175R via the proportional valve31BR is adjusted. The proportional valve 31BL can adjust the pilotpressure so that the control valve 175L and the control valve 175R canbe stopped at any valve position. The proportional valve 31BR can adjustthe pilot pressure so that the control valve 175R can be stopped at anyvalve position.

With this configuration, the controller 30 can supply the hydraulicfluid discharged from the pilot pump 15 to the right pilot port of thecontrol valve 175L and the left pilot port of the control valve 175R viathe proportional valve 31BL in response to the boom raising operation bythe operator. The controller 30 can also supply the hydraulic fluiddischarged from the pilot pump 15 to the right pilot port of the controlvalve 175L and the left pilot port of the control valve 175R via theproportional valve 31BL independently of the boom raising operation bythe operator. That is, the controller 30 can raise the boom 4 inresponse to the boom raising operation by the operator or independentlyof the boom raising operation by the operator.

In addition, the controller 30 can supply the hydraulic fluid dischargedfrom the pilot pump 15 to the right pilot port of the control valve 175Rvia the proportional valve 31BR in response to the operator's boomlowering operation. In addition, the controller 30 can supply thehydraulic fluid discharged from the pilot pump 15 to the right pilotport of the control valve 175R via the proportional valve 31BRindependently of the operator's boom lowering operation. That is, thecontroller 30 can lower the boom 4 in response to the operator's boomlowering operation or independently of the operator's boom loweringoperation.

As illustrated in FIG. 3C, the right operation lever 26R is also used tooperate the bucket 6. Specifically, the right operation lever 26Rutilizes the hydraulic fluid discharged from the pilot pump 15 to causethe pilot pressure corresponding to the operation in the left-rightdirection to act on the pilot port of the control valve 174. Morespecifically, when operated in the bucket closing direction (leftdirection), the right operation lever 26R causes the pilot pressurecorresponding to the operation amount to act on the left pilot port ofthe control valve 174. When operated in the bucket opening direction(right direction), the right operation lever 26R causes the pilotpressure corresponding to the operation amount to act on the right pilotport of the control valve 174.

The operation pressure sensor 29RB detects the contents of the operationby the operator in the right-left direction with respect to the rightoperation lever 26R, and outputs the detected value to the controller30.

A proportional valve 31CL operates in response to a control instruction(current instruction) output by the controller 30. Then, the pilotpressure by the hydraulic fluid introduced from the pilot pump 15 to theleft pilot port of the control valve 174 via the proportional valve 31CLis adjusted. A proportional valve 31CR operates in response to a controlinstruction (current instruction) output by the controller 30. The pilotpressure due to hydraulic fluid introduced from the pilot pump 15 to theright pilot port of the control valve 174 via the proportional valve31CR is adjusted. The proportional valve 31CL can adjust the pilotpressure to stop the control valve 174 at any valve position. Similarly,the proportional valve 31CR can adjust the pilot pressure to stop thecontrol valve 174 at any valve position.

With this configuration, the controller 30 can supply the hydraulicfluid discharged by the pilot pump 15 to the left pilot port of thecontrol valve 174 via the proportional valve 31CL in response to theoperator's bucket closing operation. The controller 30 can also supplythe hydraulic fluid discharged by the pilot pump 15 to the left pilotport of the control valve 174 via the proportional valve 31CLindependently of the operator's bucket closing operation. That is, thecontroller 30 can close the bucket 6 in response to the operator'sbucket closing operation or independently of the operator's bucketclosing operation.

The controller 30 can also supply the hydraulic fluid discharged by thepilot pump 15 to the right pilot port of the control valve 174 via theproportional valve 31CR in response to the operator's bucket openingoperation. The controller 30 can also supply the hydraulic fluiddischarged by the pilot pump 15 to the right pilot port of the controlvalve 174 via the proportional valve 31CR independently of theoperator's bucket opening operation. That is, the controller 30 can openthe bucket 6 in response to the operator's bucket opening operation orindependently of the operator's bucket opening operation.

As illustrated in FIG. 3D, the left operation lever 26L is also used tooperate the turning mechanism 2. Specifically, the left operation lever26L uses hydraulic fluid discharged from the pilot pump 15 to act on thepilot port of the control valve 173 with pilot pressure corresponding tooperation in the left-right direction. More specifically, when operatedin the left turning direction (left direction), the left operation lever26L acts on the left pilot port of the control valve 173 with pilotpressure corresponding to the operation amount. When operated in theright turning direction (right direction), the left operation lever 26Lacts on the right pilot port of the control valve 173 with pilotpressure corresponding to the operation amount.

The operation pressure sensor 29LB detects the contents of the operationin the left-right direction with respect to the left operation lever 26Lby the operator, and outputs the detected value to the controller 30.

A proportional valve 31DL operates in response to a control instruction(current instruction) output by the controller 30. Then, the pilotpressure by the hydraulic fluid introduced from the pilot pump 15 to theleft pilot port of the control valve 173 via the proportional valve 31DLis adjusted. A proportional valve 31DR operates in response to a controlinstruction (current instruction) output by the controller 30. The pilotpressure due to hydraulic fluid introduced from the pilot pump 15 to theright pilot port of the control valve 173 via the proportional valve31DR is adjusted. The proportional valve 31DL can adjust the pilotpressure so that the control valve 173 can be stopped at any valveposition. Similarly, the proportional valve 31DR can adjust the pilotpressure so that the control valve 173 can be stopped at any valveposition.

With this configuration, the controller 30 can supply the hydraulicfluid discharged by the pilot pump 15 to the left pilot port of thecontrol valve 173 via the proportional valve 31DL in response to theoperator's left turning operation. The controller 30 can also supply thehydraulic fluid discharged by the pilot pump 15 to the left pilot portof the control valve 173 via the proportional valve 31DL independentlyof the operator's left turning operation. That is, the controller 30 canmake the turning mechanism 2 turn left in response to the operator'sleft turning operation or independently of the operator's left turningoperation.

In addition, the controller 30 can supply the hydraulic fluid dischargedfrom the pilot pump 15 to the right pilot port of the control valve 173via the proportional valve 31DR in response to the operator's rightturning operation. Also, the controller 30 can supply the hydraulicfluid discharged by the pilot pump 15 to the right pilot port of thecontrol valve 173 via the proportional valve 31DR independently of theoperator's right turning operation. That is, the controller 30 can makethe turning mechanism 2 turn right in response to the operator's rightturning operation or independently of the operator's right turningoperation.

The shovel 100 may be configured to automatically move the lowertraveling body 1 forward and backward. In this case, the hydraulicsystem portion relating to the operation of the left traveling hydraulicmotor 2ML and the hydraulic system portion relating to the operation ofthe right traveling hydraulic motor 2MR may be configured in the samemanner as the hydraulic system portion relating to the operation of theboom cylinder 7.

Although the description of the electric operation lever has beendescribed as a form of the operation device 26, a hydraulic operationlever may be used instead of the electric operation lever. In such acase, the lever operation amount of the hydraulic operation lever may bedetected in the form of pressure by a pressure sensor and input to thecontroller 30. A solenoid valve may be disposed between the operationdevice 26 as the hydraulic operation lever and the pilot port of eachcontrol valve. The solenoid valve is configured to operate in responseto an electrical signal from the controller 30. With this configuration,when a manual operation using the operation device 26 as a hydraulicoperation lever is performed, the operation device 26 can move eachcontrol valve by increasing or decreasing the pilot pressure accordingto the lever operation amount. Further, each control valve may becomposed of a solenoid spool valve. In this case, the solenoid spoolvalve operates in response to an electric signal from the controller 30corresponding to the lever operation amount of the electric operationlever. Next, the functions of the controller 30 will be described withreference to FIG. 4 . FIG. 4 is a functional block diagram of thecontroller 30. In the example of FIG. 4 , the controller 30 isconfigured to receive signals output from an attitude detection device,the operation device 26, the object detection device 70, the imagingdevice 80, the switch NS, etc., perform various operations, and outputcontrol instructions to the proportional valve 31, the display deviceD1, the sound output device D2, etc. The attitude detection deviceincludes, for example, a boom angle sensor S1, an arm angle sensor S2, abucket angle sensor S3, a body inclination sensor S4, and a turningangular velocity sensor S5. The controller 30 has a trajectorygeneration part and an autonomous control part 30B as functional blocks.Each functional block may be composed of hardware or software.

The trajectory generation part 30A is configured to generate a targettrajectory which is a trajectory plotted by a predetermined part of theshovel 100 when the shovel 100 is operated autonomously. Thepredetermined part is, for example, a claw end of the bucket 6 or apredetermined point on the back surface of the bucket 6. In the presentembodiment, the trajectory generation part 30A generates a targettrajectory that the autonomous control part 30B uses to autonomouslyoperate the shovel 100. Specifically, the trajectory generation part 30Agenerates a target trajectory based on an output of at least one of theobject detection device 70 and the imaging device 80.

The autonomous control part 30B is configured to operate the shovel 100autonomously. In the present embodiment, the autonomous control part 30Bis configured to move a predetermined part of the shovel 100 along atarget trajectory generated by the trajectory generation part 30A when apredetermined start condition is satisfied. Specifically, the autonomouscontrol part 30B autonomously operates the shovel 100 so that thepredetermined part of the shovel 100 moves along the target trajectorywhen the operation device 26 is operated while the switch NS is pressed.For example, the autonomous control part 30B autonomously operates theexcavation attachment AT so that the claw end of the bucket 6 movesalong the target trajectory when the left operation lever 26L isoperated in the arm opening direction while the switch NS is pressed.The autonomous control part 30B may operate the shovel 100 autonomouslyso that the predetermined part of the shovel 100 moves along the targettrajectory when the switch NS is pressed, regardless of whether theoperation device 26 is operated.

Next, with reference to FIGS. 5 and 6 , an example of a function(hereinafter referred to as “autonomous control function”) in which thecontroller 30 autonomously controls the movement of the attachment willbe described. FIGS. 5 and 6 are block diagrams illustrating theautonomous control function.

First, as illustrated in FIG. 5 , the controller 30 determines thetarget movement speed and the target movement direction based on theoperation inclination. The operation inclination is determined based on,for example, the lever operation amount. A target moving velocity is atarget value of the moving velocity of a control reference point, and atarget moving direction is a target value of a moving direction of thecontrol reference point. The control reference point is, for example, aclaw end of the bucket 6 or a predetermined point on the back surface ofthe bucket 6. The control reference point is calculated based on, forexample, the boom angle β₁, the arm angle the bucket angle β₃, and theturning angle α₁.

Thereafter, the controller 30 calculates three-dimensional coordinates(Xer, Yer, Zer) of the control reference point after the unit time haselapsed, based on the target moving velocity, the target movingdirection, and three-dimensional coordinates (Xe, Ye, Ze) of the controlreference point. The three-dimensional coordinates (Xer, Yer, Zer) ofthe control reference point after the unit time has elapsed are, forexample, coordinates on the target trajectory. The unit time is, forexample, the time equivalent to an integer multiple of the controlperiod. The target trajectory may be, for example, target trajectoryrelating to a backfilling operation performed for a backfilling work,which is a work for backfilling a hole. The backfilling operationincludes an operation of releasing a sediment as an example of a mass ofearth and sand put in the bucket 6 into the hole, and an operation ofpushing a sediment placed around the hole with the bucket 6 into thehole. Typically, the backfilling operation is a combined operationincluding the bucket opening operation and the arm opening operation. Inthis case, the target trajectory may be calculated based on at least oneof, for example, the shape of the hole opening, the depth of the hole,the volume of the sediment already released into the hole, and thevolume of the sediment put into the bucket 6. The shape of the hole, thedepth of the hole, the volume of sediment already released into thehole, and the volume of the sediment put into the bucket 6 may bederived based on, for example, an output of at least one of the objectdetection device 70 and the imaging device 80. For example, the targettrajectory may be set so that the variation in depth of each part of thehole is not significantly large. That is, the target trajectory may beset so that only a part of the hole is not intensively backfilled.Conversely, the target trajectory may be set so that only a part of thehole is intensively backfilled.

The target trajectory is typically calculated before the backfillingoperation starts, and is not changed until the backfilling operationends. However, the target trajectory may be changed during the executionof the backfilling operation. That is, a content of the backfillingoperation may be changed.

Thereafter, the controller 30 generates instruction values β_(1r),β_(2r), and β_(3r) relating to the rotations of the boom 4, the arm 5,and the bucket 6, and an instruction value air relating to the turningof the upper turning body 3, based on the calculated three-dimensionalcoordinates (Xer, Yer, Zer). The instruction value β_(1r) represents,for example, the boom angle β₁ when the control reference point can beadjusted to the three-dimensional coordinates (Xer, Yer, Zer).Similarly, the instruction value β_(2r) represents an arm angle β₂ whenthe control reference point can be adjusted to the three-dimensionalcoordinates (Xer, Yer, Zer), the instruction value β_(3r) represents abucket angle β₃ when the control reference point can be adjusted to thethree-dimensional coordinates (Xer, Yer, Zer), and the instruction valueair represents a turning angle α₁ when the control reference point canbe adjusted to the three-dimensional coordinates (Xer, Yer, Zer).

The instruction value β_(3r) for the rotation of the bucket 6 may bechanged during the execution of the backfilling operation. For example,the instruction value β_(3r) may be adjusted smaller when the depth ofthe hole in the backfilled portion becomes shallower than the desireddepth. That is, the instruction value β_(3r) is typically controlled byopen-loop control, but may be feedback controlled according to the depthof the hole in the backfilled portion. Thereafter, as illustrated inFIG. 6 , the controller 30 operates the boom cylinder 7, the armcylinder 8, the bucket cylinder 9, and the turning hydraulic motor 2A sothat the boom angle β₁, the arm angle β₂, the bucket angle β₃, and theturning angle α₁ have the generated instruction values β_(1r), β_(2r),β_(3r), and α_(1r), respectively. The turning angle α₁ is calculatedbased on an output of the turning angular velocity sensor S5, forexample.

Specifically, the controller 30 generates a boom cylinder pilot pressureinstruction corresponding to the difference Δβ₁ between a current valueand the instruction value β_(1r) of the boom angle β₁. A control currentcorresponding to the boom cylinder pilot pressure instruction is outputto a boom control mechanism 31B. The boom control mechanism 31B isconfigured so that a pilot pressure in response to a control currentcorresponding to the boom cylinder pilot pressure instruction can beapplied to the control valve 175 as a boom control valve. The boomcontrol mechanism 31B may be, for example, the proportional valve 31BLand the proportional valve 31BR in FIG. 3B.

Thereafter, the control valve 175 that has received the pilot pressuregenerated by the boom control mechanism 31B causes the hydraulic fluiddischarged from the main pump 14 to flow into the boom cylinder 7 in theflow direction and flow rate corresponding to the pilot pressure.

At this time, the controller 30 may generate a boom spool controlinstruction based on a displacement amount of the spool of the controlvalve 175 detected by the boom spool displacement sensor S7. The boomspool displacement sensor S7 is a sensor configured to detect thedisplacement amount of a spool constituting the control valve 175. Thecontroller 30 may output a control current corresponding to the boomspool control instruction to the boom control mechanism 31B. In thiscase, the boom control mechanism 31B applies a pilot pressure inresponse to the control current corresponding to the boom spool controlinstruction to the control valve 175.

The boom cylinder 7 extends and retracts by hydraulic fluid supplied viathe control valve 175. The boom angle sensor S1 detects the boom angleβ₁ of the boom 4 moved by extending and retracting the boom cylinder 7.

Thereafter, the controller 30 feeds back the boom angle β₁ detected bythe boom angle sensor S1 as a current value of the boom angle β₁ used ingenerating the boom cylinder pilot pressure instruction.

Although the above description relates to the operation of the boom 4based on the instruction value β_(1r), the same applies to the operationof the arm 5 based on the instruction value β_(2r), the operation of thebucket 6 based on the instruction value β_(3r), and the turningoperation of the upper turning body 3 based on the instruction valueair. An arm control mechanism 31A is configured so that a pilot pressurein response to a control current corresponding to an arm cylinder pilotpressure instruction can be applied to the control valve 176 as an armcontrol valve. The arm control mechanism 31A may be, for example, theproportional valve 31AL and the proportional valve 31AR in FIG. 3A. Abucket control mechanism 31C is configured so that a pilot pressure inresponse to a control current corresponding to a bucket cylinder pilotpressure instruction can be applied to the control valve 174 as a bucketcontrol valve. The bucket control mechanism 31C may be, for example, theproportional valve 31CL and the proportional valve 31CR in FIG. 3C. Aturning control mechanism 31D is configured so that a pilot pressure inresponse to a control current corresponding to a turning hydraulic motorpilot pressure instruction can be applied to the control valve 173 as aturning control valve. The turning control mechanism 31D may be, forexample, the proportional valve 31DL and the proportional valve 31DR inFIG. 3D. An arm spool displacement sensor S8 is a sensor configured todetect the displacement amount of a spool constituting the control valve176, a bucket spool displacement sensor S9 is a sensor configured todetect a displacement amount of a spool constituting the control valve174, and a turning spool displacement sensor S6 is a sensor configuredto detect a displacement amount of a spool constituting the controlvalve 173.

As illustrated in FIG. 5 , the controller 30 may derive pump dischargeamounts from the instruction values β_(1r), β_(2r), β_(3r), and airusing the pump discharge amount deriving parts CP1, CP2, CP3, and CP4.In the present embodiment, the pump discharge amount deriving parts CP1,CP2, CP3, and CP4 derive the pump discharge amounts from the instructionvalues β_(1r), β_(2r), β_(3r), and air using a pre-registered referencetable or the like. The pump discharge amounts derived by the pumpdischarge amount deriving parts CP1, CP2, CP3, and CP4 are summed andinput to a pump flow calculation part as a total pump discharge amount.The pump flow calculation part controls the discharge amount of the mainpump 14 based on the input total pump discharge amount. In the presentembodiment, the pump flow calculation part controls the discharge amountof the main pump 14 by changing a swash plate inclination angle of themain pump 14 according to the total pump discharge amount.

Thus, the controller 30 can perform control of respective openings ofthe control valve 175 as the boom control valve, the control valve 176as the arm control valve, the control valve 174 as the bucket controlvalve, and the control valve 173 as the turning control valve,simultaneously with performing control of the discharge amount of themain pump 14. Therefore, the controller 30 can supply an appropriateamount of hydraulic fluid to each of the boom cylinder 7, the armcylinder 8, the bucket cylinder 9, and the turning hydraulic motor 2A.

The controller 30 calculates three-dimensional coordinates (Xer, Yer,Zer), generates instruction values β_(1r), β_(2r), β_(3r), and α_(1r),and determines a discharge amount of the main pump 14 as one controlcycle, and repeats this control cycle to execute autonomous control. Thecontroller can improve the accuracy of autonomous control by feedbackcontrolling the control reference point based on the respective outputsof the boom angle sensor S1, the arm angle sensor S2, the bucket anglesensor S3, and the turning angular velocity sensor S5. Specifically, thecontroller 30 can improve the accuracy of autonomous control by feedbackcontrolling the flow rates of hydraulic fluid flowing into the boomcylinder 7, the arm cylinder 8, the bucket cylinder 9, and the turninghydraulic motor 2A.

Further, the controller 30 may be configured to monitor the distancebetween the bucket 6 and the surrounding obstacles so that the bucket 6does not come into contact with the surrounding obstacles whenperforming autonomous control for the backfilling operation. Forexample, the controller 30 may stop the movement of the excavationattachment AT when determining that the distance between one or each ofa plurality of predetermined points in the bucket 6 and the surroundingobstacles falls below a predetermined value based on the outputs of theattitude detection device and the object detection device 70.

Next, with reference to FIGS. 7A to 7C and FIGS. 8A to 8C, an example ofautonomous control for the backfilling operation will be described.FIGS. 7A to 7C are top views illustrating the shovel 100 performing thebackfilling operation and a hole HL subject to the backfillingoperation. FIGS. 8A to 8C are cross-sectional views illustrating thehole HL. The controller 30 recognizes a position of the hole HL as anobject subject to the backfilling operation (the position to bebackfilled) and generates a target trajectory from the sediment pile (anexcavation completion position) to the hole HL.

The excavation completion position may be set to the position of thebucket 6 when the sediment is put into the bucket 6. Alternatively, theexcavation completion position may be set to the position of the bucket6 when the bucket 6 is lifted by a predetermined height from theposition of the bucket 6 when the sediment is put into the bucket 6.

The controller 30 may recognize the shape (opening area, depth, etc.) ofthe hole HL or a position of the hole HL based on the output of theobject detection device 70, and set a target position relating to thebackfilling operation. The controller 30 may recognize the uneven shapeof a landform based on the output of the object detection device 70, anddisplay the recognized uneven shape on the display device D1. In thiscase, the controller 30 may display a frame or marker or the like on theimage of the hole HL or the uneven shape or the like (hereinafterreferred to as “hole HL or the like”) displayed on the display device D1so that the operator of the shovel 100 can recognize the hole HL or thelike. The image of the hole HL or the like is included in the capturedimage output from the imaging device (object detection device 70). Then,the controller 30 can set a target position for the hole HL or the likeby setting input (selection) of the hole HL or the like to be recognizedby the operator. The operator may select an image of the hole HL or thelike to be backfilled from the captured image displayed on the displaydevice D1, and set the selected image as a target position. In thiscase, the actual position in a landform region displayed on the displaydevice D1 is associated with the position of the image in a displayregion of the display device D1. Therefore, by the operator selecting apredetermined position in the display region of the display device D1,the controller 30 can recognize the actual position of the hole HLrelative to the shovel 100 and set the target position for backfilling.

In this manner, the controller 30 generates a trajectory up to the settarget position as the target trajectory. Typically, the target positionis set above the bottom of the hole HL. The target position is alsotypically set inside the contour of the hole HL.

Specifically, FIGS. 7A and 8A illustrate a state when a firstbackfilling operation by autonomous control is completed. A shovelfigure represented by the broken line in FIG. 7A illustrates a state ofthe shovel 100 after the first excavation operation by manual operationis completed and before the first backfilling operation is started. Asediment R1 represents a sediment released into the hole HL by the firstbackfilling operation. The sediment R1 is released into a portion of thehole HL farthest from the shovel 100, for example. In the stateillustrated in FIGS. 7A and 8A, the controller 30 generates a targettrajectory between the positions of the sediment pile and the farthestportion of the hole HL. The controller 30 may change the target positionat each backfilling operation. As a result, the target position and thetarget trajectory at the second or third backfilling operation arechanged. The target position and the timing for the change of the targettrajectory may be changed according to the shape (size or depth, etc.)of the hole HL.

FIGS. 7B and 8B illustrate a state when a second backfilling operationby autonomous control is completed. The shovel figure represented by thebroken line in FIG. 7B represents a state of the shovel 100 after thesecond excavation operation by manual operation is completed and beforethe second backfilling operation is started. A sediment R2 represents asediment released into the hole HL by the second backfilling operation.The sediment R2 is released into a portion of the hole HL closer to theshovel 100 than the sediment R1, for example, so as to be adjacent tothe sediment R1. In the state illustrated in FIGS. 7B and 8B, thecontroller 30 updates the target trajectory generated in the stateillustrated in FIGS. 7A and 8A.

FIGS. 7C and 8C illustrate the state when a third backfilling operationby autonomous control is completed. The shovel figure represented by thebroken line in FIG. 7C represents a state of the shovel 100 after athird excavation operation by manual operation is completed and beforethe third backfilling operation is started. A sediment R3 represents asediment released into the hole HL by the third backfilling operation.The sediment R3 is, for example, released to a portion of the hole HLcloser to the shovel 100 than the sediment R2 so as to be adjacent tothe sediment R2. In the state illustrated in FIGS. 7C and 8C, thecontroller 30 updates the target trajectory that has been updated in thestate illustrated in FIGS. 7B and 8B. Note that the controller 30 mayrecognize the shape of the sediment dropped into the hole HL based onthe output from the imaging device 80 (object detection device 70). Forexample, the controller 30 may estimate the shape of the sedimentdropped into the hole HL based on the shape of the hole HL, the sedimentcharacteristics, the dropped position, and the like. Thus, thecontroller 30 can change the target position in the next backfillingoperation by identifying the shape of the sediment dropped into the holeHL.

The operator of the shovel 100 executes the first backfilling operationby autonomous control by pressing the switch NS at the time beforestarting the first backfilling operation, i.e., when the state of theshovel 100 is set to the state indicated by the broken line in FIG. 7A.In the example illustrated in FIGS. 7A to 7C and FIGS. 8A to 8C, theshovel 100 is configured to execute the backfilling operation when theswitch NS is pressed, but the shovel 100 may be configured to executethe backfilling operation when the left operation lever 26L is operatedin the right turning direction while the switch NS is pressed.

In the example illustrated in FIG. 7A, the target trajectory for thefirst backfilling operation is generated based on a current claw endposition AP1 of the bucket 6 and a claw end position BP1 of the bucket 6when the first backfilling operation is completed. The position BP1 isset such that, for example, the claw end of the bucket 6 is positioneddirectly above the center point of the sediment R1. The sediment R1 is asediment to be put into the hole HL by the first backfilling operation.

Thereafter, the controller 30 executes the first backfilling operationby autonomous control using the calculated target trajectory.Specifically, the controller automatically turns the upper turning body3 to the right to automatically expand and contract the excavationattachment AT so that the trajectory plotted by the claw end of thebucket 6 follows the target trajectory.

After the first backfilling operation by autonomous control iscompleted, the operator of the shovel 100 performs an intermediateoperation including a manually operated left-turning operation to bringthe bucket 6 closer to a sediment pile F1 illustrated in FIG. 7A. Thisintermediate operation for moving the claw end of the bucket 6 from theposition when the backfilling operation is completed to the positionwhen the next excavation operation is started may be performedautonomously without the operator's manual operation and may beperformed semi-autonomously to assist the operator's manual operation.When this intermediate operation is performed autonomously, a targettrajectory for this intermediate operation is generated based on acurrent claw end position BP1 of the bucket 6 and a claw end positionDP1 of the bucket 6 at the start of the second excavation operation. Forexample, the position DP1 is set to be located directly above the centerpoint of the sediment pile F1. The semi-autonomous operation differsfrom the autonomous operation in that the semi-autonomous operation isexecuted in response to the manual operation of the operation lever bythe operator, but the semi-autonomous operation is common to theautonomous operation in that the claw end of the bucket 6 is moved alongthe target trajectory.

Thereafter, the operator puts the sediment constituting the sedimentpile F1 into the bucket 6 by a manually operated excavation operation.Thereafter, the operator executes the second backfilling operation byautonomous control by pressing the switch NS at a time after theexcavation operation is finished, that is, when the state of the shovel100 is set to the state indicated by the broken line in FIG. 7B.

In the example illustrated in FIG. 7B, the target trajectory for thesecond backfilling operation is generated based on a current claw endposition AP2 of the bucket 6 and a claw end position BP2 of the bucket 6when the second backfilling operation is completed. The position BP2 isset such that, for example, the claw end of the bucket 6 is positioneddirectly above the center point of the sediment R2. The sediment R2 is asediment to be put into the hole HL by the second backfilling operation.

Thereafter, the controller 30 executes the second backfilling operationby autonomous control using the calculated target trajectory.Specifically, the controller automatically right-turns the upper turningbody 3 and automatically extends and retracts the excavation attachmentAT so that the trajectory plotted by the claw end of the bucket 6follows the target trajectory.

After the second backfilling operation by autonomous control iscompleted, the operator of the shovel 100 performs an intermediateoperation including a manually operated left-turning operation to bringthe bucket 6 closer to a sediment pile F2 illustrated in FIG. 7B. Thisintermediate operation may be performed autonomously without theoperator's manual operation and may be performed semi-autonomously toassist the operator's manual operation. When this intermediate operationis performed autonomously, a target trajectory for this intermediateoperation is generated based on a current claw end position BP2 of thebucket 6 and a claw end position DP2 of the bucket 6 at the start of thethird excavation operation. The position DP2 is set to be locateddirectly above the center point of the sediment pile F2, for example.

Then, the operator puts a sediment constituting the sediment pile F2into the bucket 6 by manually operated excavation operation. Then, theoperator executes the third backfilling operation by autonomous controlby pressing the switch NS at a time after the excavation operation isfinished, that is, when the state of the shovel 100 is set to the stateindicated by the broken line in FIG. 7C.

In this manner, the controller 30 can reduce the operator's burden onthe manual backfilling operation by executing the backfilling operationautonomously. In the above-described embodiment, the intermediateoperation and the excavation operation are executed in response to theoperator's manual operation; however, at least one of the intermediateoperation and the excavation operation may be executed autonomously orsemi-autonomously by the controller in the same manner as thebackfilling operation.

Referring to FIGS. 9A and 9B, an example of a leveling operationperformed after the hole HL is backfilled will be described. FIGS. 9Aand 9B are cross-sectional views illustrating the backfilled hole HL,which correspond to FIGS. 8A to 8C. Specifically, FIGS. 9A and 9Billustrate a state of the sediment backfilled into the hole HL by aplurality of backfilling operations. More specifically, FIG. 9Aillustrates a state of the sediment in the hole HL before the levelingoperation is performed, and FIG. 9B illustrates a state of the sedimentin the hole HL after the leveling operation is performed. In FIGS. 9Aand 9B, for clarity, the ground around the hole HL is marked with ashaded pattern, and the sediment backfilled in the hole HL is markedwith a dot pattern.

In the present embodiment, the controller 30 is configured to set theheight of a target surface TS before the backfilling operation isperformed. The target surface TS is a virtual surface corresponding tothe ground formed when a hole HL to be backfilled is backfilled with asediment, and is typically a virtual horizontal plane. The controllerdetects, for example, the hole HL and a surrounding surface CS, which isthe ground around the hole HL, based on the output of the objectdetection device 70. The controller sets a height of the target surfaceTS based on a height of the detected surrounding surface CS. The heightof the target surface TS is typically set to be the same as the heightof the surrounding surface CS. Respective dashed one-dotted linesillustrated in FIGS. 9A and 9B represent the target surface TS.

The controller 30 then determines, for example, whether the hole HL hasbeen backfilled with the sediment based on the output of the objectdetection device 70. In the example illustrated in FIGS. 9A and 9B, thecontroller determines that the hole HL has been backfilled with thesediment when the entire target surface TS has been backfilled with thesediment. The controller 30 then executes an autonomous levelingoperation when determining that the hole HL has been backfilled with thesediment. The backfilling operation executed prior to the levelingoperation is executed so that the height of the sediment backfilled inthe hole HL is slightly higher than the height of the target surface TS.

When determining that the hole HL has been backfilled with the sediment,the controller 30 generates a target trajectory along the target surfaceTS, and performs a leveling operation by automatically moving the clawend of the bucket 6 in a direction away from the shovel 100 along thetarget trajectory. In this case, the leveling operation is a combinedoperation including an arm opening operation. FIG. 9A illustrates aposition of the bucket 6 when the leveling operation is started, andFIG. 9B illustrates a position of the bucket 6 when the levelingoperation is completed. The controller 30 may set the target surface TSbased on the height of the landform adjacent to the hole HL.Alternatively, the controller 30 may set the target surface TS based onthe height of the sediment backfilled in the hole HL or the sedimentshape. Alternatively, the controller may set the target surface TS basedon the construction plan (design data).

This configuration enables the controller 30 to level a surface of thesediment backfilled in the hole HL so that the surface of the sedimentbackfilled in the hole HL has no irregularities. Also, thisconfiguration enables the controller 30 to make the height of thesurface of the sediment backfilled in the hole HL and the height of thesurrounding surface CS substantially the same.

Next, referring now to FIGS. 10A and 10B, another example of autonomouscontrol for the backfilling operation will be described. FIG. 10A is atop view illustrating the shovel 100 when the backfilling operation isperformed and the hole HL subject to the backfilling operation, whichcorresponds to FIGS. 7A to 7C. FIG. 10B is a cross-sectional viewillustrating the hole HL, which corresponds to FIGS. 8A to 8C.

In the example illustrated in FIGS. 10A and 10B, the controller 30 isconfigured to push a sediment into the hole HL by pushing it off withthe bucket 6 without lifting the sediment with the bucket 6 when thesediment to be backfilled into the hole HL is within a predetermineddistance range from the hole HL. In the example illustrated in FIGS. 10Aand 10B, the controller 30 uses a back face BF of the bucket 6 toautonomously perform a push-off operation to push off a sedimentconstituting a sediment pile F10 within the predetermined distance rangefrom the hole HL into the hole HL. In FIG. 10A, the predetermineddistance range is a range Z1 surrounded by a broken line.

Specifically, as illustrated in FIG. 10B, the controller 30 autonomouslyoperates the excavation attachment AT so as to push the sedimentconstituting the sediment pile F10 into the hole HL by two backfillingoperations (push-off operations).

For example, the controller 30 recognizes a position and a shape of thesediment pile F10 based on the output of the object detection device 70.Based on the recognized position and shape of the sediment pile F10, thecontroller 30 generates a target trajectory TL for pushing the sedimentconstituting the sediment pile F10 into the hole HL. At this time, thecontroller 30 may calculate the volume or weight of the sedimentconstituting the sediment pile F10. There is a limit on the volume orweight of the sediment that can be pushed off by a single push-offoperation, so that the target trajectory can be generated so as not toexceed this limit.

FIG. 10B illustrates a target trajectory TL1, which is a part of thetarget trajectory TL for the first push-off operation, as a dashedone-dotted line, and a target trajectory TL2, which is a part of thetarget trajectory TL for the second push-off operation, as a dashed-twodotted line. FIGS. 10A and 10B illustrate a state of the bucket 6 whenthe first push-off operation is completed as a solid line, and a stateof the bucket 6 when the first push-off operation is started as a bucketFIG. 6A plotted with a broken line. Further, FIG. 10B illustrates asediment F10T pushed into the hole HL by the first push-off operationout of the sediment pile F10 as a solid line, and a portion F10T1corresponding to the sediment F10T of the sediment pile F10 before thefirst push-off operation is started as a broken line.

A sediment F10B, which remains even after the first push-off operationamong the sediments constituting the sediment pile F10, is pushed intothe hole HL by the second push-off operation, that is, by moving theclaw end of the bucket 6 from the side close to the shovel 100 to thefar side along the target trajectory TL2.

By executing the push-off operation as described above, the controller30 can push the sediment relatively close to the hole HL into the holeHL. In the example described above, the controller 30 is configured toexecute the push-off operation for dropping a sediment into the hole HLusing the back face BF of the bucket 6, but may be configured to executea push-off operation for dropping a sediment into the hole HL using afront face or a side face of the bucket 6. For example, the controller30 may be configured to execute the push-off operation for dropping asediment into the hole HL using the front face of the bucket 6 whendropping the sediment constituting a sediment pile F11 on the +X side(side far from the shovel 100) of the hole HL in the range Z1.

The controller 30 may also be configured to release a sediment, whichhas been put into the bucket 6 and lifted by the excavation operation,into the hole HL as described with reference to FIGS. 7A to 7C and FIGS.8A to 8C when the sediment to be backfilled into the hole HL is outsidethe predetermined distance range from the hole HL. Specifically, withrespect to a sediment pile F12 outside the range Z1, the controller 30may be configured to release a sediment constituting the sediment pileF12, which has been put into the bucket 6 and lifted by the excavationoperation, into the hole HL by an autonomous backfilling operation.

In the example illustrated in FIGS. 10A and 10B, the controller 30 maybe configured to perform the push-off operation when the switch NS ispressed, but may be configured to perform the push-off operation whenthe left operation lever 26L is operated in the arm opening directionwhile the switch NS is pressed.

Next, with reference to FIG. 11 , a backfilling operation (push-offoperation) for dropping the sediment into the hole HL using the sideface of the bucket 6 will be described. FIG. 11 is a top viewillustrating the shovel 100 when the backfilling operation (push-offoperation) is performed and the hole HL subject to the backfillingoperation (push-off operation), which corresponds to FIG.

In the example illustrated in FIG. 11 , the controller 30 is configuredto push the sediment into the hole HL by pushing off the sediment withthe bucket 6, without lifting the sediment with the bucket 6, when thesediment to be backfilled in the hole HL is within a predetermineddistance range from the hole HL, as in the example illustrated in FIGS.10A and 10B. When the sediment to be backfilled in the hole HL isoutside the predetermined distance range from the hole HL, thecontroller 30 is configured to put the sediment into the bucket 6 andlift the sediment in the bucket 6 by the excavation operation, and thenrelease the sediment put in the bucket 6 into the hole HL, as describedwith reference to FIGS. 7A to 7C and FIGS. 8A to 8C.

In the example illustrated in FIG. 11 , the controller 30 uses a sideface SF (left-side face LSF) of the bucket 6 to autonomously execute apush-off operation to push a sediment constituting a sediment pile F13within a predetermined distance range from the hole HL into the hole HL.In FIG. 11 , the predetermined distance range is a range Z1 surroundedby a broken line.

Specifically, as illustrated in FIG. 11 , the controller 30 isconfigured to autonomously turn the upper turning body 3 to the left soas to push the sediment constituting the sediment pile F13 into the holeHL by two backfilling operations (push-off operations).

For example, the controller 30 recognizes a position and a shape of thesediment pile F13 based on the output of the object detection device 70.Then, the controller 30 generates a target trajectory TL for pushing thesediment constituting the sediment pile F13 into the hole HL based onthe recognized position and shape of the sediment pile F13. At thistime, the controller 30 may calculate the volume or weight of thesediment constituting the sediment pile F13. There is a limit on thevolume or weight of the sediment that can be pushed off by a singlepush-off operation, so that the target trajectory TL can be generated soas not to exceed this limit.

FIG. 11 illustrates a target trajectory TL3, which is a part of thetarget trajectory TL for the first push-off operation, as a dashedone-dotted line. FIG. 11 illustrates a state of the bucket 6 when thefirst push-off operation is completed as a solid line, and the positionof the bucket 6 when the first push-off operation is started as a bucketFIG. 6B plotted as a broken line. Further, FIG. 11 illustrates asediment F13T which has been pushed into the hole HL by the firstpush-off operation among the sediment constituting the sediment pileF13, and a sediment F13B which remains after the first push-offoperation among the sediment constituting the sediment pile F10 withsolid lines.

The sediment F13T is pushed into the hole HL by the first push-offoperation, that is, by moving the claw end of the bucket 6 from right toleft along the target trajectory TL3.

The sediment F13B is pushed into the hole HL by the second push-offoperation, that is, by moving the claw end of the bucket 6 from right toleft along a target trajectory (not illustrated) for the second push-offoperation.

By performing the push-off operation including the turning operationdescribed above, the controller 30 can push the sediment relativelyclose to the hole HL into the hole HL. In the example described above,the controller 30 is configured to perform the push-off operation fordropping the sediment into the hole HL using the left-side face LSF ofthe bucket 6, but the controller 30 may be configured to perform thepush-off operation for dropping the sediment into the hole HL using aright-side face of the bucket 6. For example, the controller 30 may beconfigured to perform the push-off operation for dropping the sedimentinto the hole HL using the right-side face of the bucket 6 when thesediment constituting the sediment pile on the +Y side of the hole HL inthe range Z1 is dropped into the hole HL.

Next, referring to FIGS. 12A to 12C, yet another example of autonomouscontrol for the backfilling operation will be described. FIGS. 12A to12C are cross-sectional views illustrating the hole HL, which correspondto FIGS. 9A and 9B. Specifically, FIGS. 12A to 12C illustrate states ofa sediment GR backfilled in the hole HL by a plurality of backfillingoperations. More specifically, FIG. 12A illustrates a state of thesediment GR in the hole HL before a second-to-last backfilling operation(push-off operation) is performed, FIG. 12B illustrates a state of thesediment in the hole HL after the second-to-last backfilling operation(push-off operation) is performed, and FIG. 12C illustrates a state ofthe sediment in the hole HL after the last backfilling operation(push-off operation) is performed.

In the example illustrated in FIGS. 12A to 12C, the controller 30 isconfigured to set the height of the target surface TS before thebackfilling operation is performed. The target surface TS is a virtualsurface, typically a virtual horizontal plane, which corresponds to theground formed when the hole HL to be backfilled is backfilled withsediment. The controller 30 detects, for example, the hole HL and thesurrounding surface CS, which is the ground around the hole HL, based onthe output of the object detection device 70. The controller 30 sets theheight of the target surface TS based on the height of the detectedsurrounding surface CS. The height of the target surface TS is typicallyset to be the same as the height of the surrounding surface CS. Thelower dashed one-dotted line illustrated in FIG. 12A represents thetarget surface TS.

The controller 30 determines, for example, based on the output of theobject detection device 70, whether or not a sediment pile exists withina predetermined distance range from the hole HL. When the sediment pileexists within the predetermined distance range from the hole HL, thecontroller 30 calculates a volume of a sediment constituting thesediment pile, for example, based on the output of the object detectiondevice 70. The sediment pile that exists within the predetermineddistance range from the hole HL is a pile of sediment to be pushed intothe hole HL by a push-off operation, and is hereinafter referred to asan “adjacent sediment pile”. In the example illustrated in FIGS. 12A to12C, the controller 30 recognizes that a sediment pile F14 exists as anadjacent sediment pile on the −X side of the hole HL (the side close tothe shovel 100). Therefore, the controller 30 calculates the volume ofthe sediment constituting the sediment pile F14.

For example, every time the backfilling operation is completed, thecontroller 30 calculates a volume (required volume) of the sedimentrequired to completely backfill the hole HL based on the output of theobject detection device 70. The required volume corresponds to a volume(excluding the volume of the part already backfilled with the sediment)of the space located below the target surface TS in the hole HL. Then,the controller 30 determines whether the volume of the sedimentconstituting the adjacent sediment pile (sediment pile F14) is equal toor greater than the required volume. It should be noted that thecontroller 30 is typically configured to adjust the volume of thesediment to be backfilled into the hole HL by the preceding backfillingoperation so that the required volume is approximately equal to thevolume of the adjacent sediment pile.

When determining that the volume of sediment constituting the adjacentsediment pile (sediment pile F14) is equal to or greater than therequired volume, the controller 30 executes an autonomous push-offoperation as an autonomous backfilling operation.

Specifically, the controller 30 generates a target trajectory TL forpushing the sediment constituting the sediment pile F14 into the hole HLbased on the position and shape of the sediment pile F14. In this case,the controller may set a target position with respect to the hole HL,and generate a target trajectory TL.

FIGS. 12A and 12B illustrate a target trajectory TL4, which is a part ofthe target trajectory TL for a second-to-final push-off operation, as adashed one-dotted line. FIGS. 12B and 12C illustrate a target trajectoryTL5, which is a part of the target trajectory TL for a final push-offoperation, as a dashed two-dotted line.

FIG. 12A illustrates a state of the bucket 6 as a solid line when thesecond-to-final push-off operation is started. FIG. 12B illustrates astate of the bucket 6 as a solid line when the final push-off operationis started, and illustrates the sediment F14T pushed into the hole HL bythe second-to-final push-off operation from among the sedimentsconstituting the sediment pile F14 as a coarse dot pattern. FIG. 12Cillustrates a state of the bucket 6 as a solid line when the finalpush-off operation is completed. In FIGS. 12A to 12C, for clarity, afine dot pattern is attached to the sediment GR and the sediment pileF14 (excluding sediment F14T), and a shaded pattern is attached to theground around the hole HL.

As illustrated in FIG. 12B, a sediment F14B, which has remained afterthe second-to-final push-off operation of the sediment pile F14, ispushed into the hole HL by the final push-off operation, that is, bymoving the claw end of the bucket 6 along the target trajectory TL5 fromthe side close to the shovel 100 to the side away from the shovel, asillustrated in FIG. 12C.

By executing the push-off operation as described above, the controller30 is able to push the sediment relatively close to the hole HL into thehole HL at the same time as leveling the surface of the sedimentbackfilled into the hole HL, so that the surface of the sedimentbackfilled into the hole HL has no irregularities. In addition, thecontroller 30 can make the height of the surface of the sedimentbackfilled into the hole HL and the height of the surrounding surface CSsubstantially the same. Note that, in the example illustrated in FIGS.12A to 12C, the controller is configured to perform the push-offoperation for dropping the sediment into the hole HL and the levelingoperation simultaneously by using the back face BF of the bucket 6, butmay be configured to perform the push-off operation for dropping thesediment into the hole HL and the leveling operation simultaneously byusing the front face or the side face of the bucket 6.

Thus, the controller 30 autonomously and simultaneously performs thebackfilling operation and the leveling operation, thereby reducing theoperator's burden on the backfilling operation and the levelingoperation by manual operation. In addition, the controller 30 canenhance the efficiency of the backfilling operation compared with thecase where the backfilling operation and the leveling operation areperformed separately.

As described above, the shovel 100 according to the embodiment of thepresent disclosure includes a lower traveling body 1, an upper turningbody 3 turnably mounted on the lower traveling body 1, and thecontroller 30 as a control device disposed in the upper turning body 3.The controller 30 is configured to start an autonomous backfillingoperation by the shovel 100 when a predetermined condition is met.

The predetermined condition is, for example, a condition in which apredetermined switch has been operated, or a condition in which theoperation lever has been operated in a predetermined direction in apredetermined operation mode.

The predetermined switch is, for example, a switch NS disposed on theoperation lever. The predetermined operation mode is, for example, abackfilling mode. The operator of the shovel 100 can switch an operationmode of the shovel 100 between a normal mode and the backfilling modeby, for example, operating the switch NS. When the operation mode of theshovel 100 is the backfilling mode, the operator can perform anautonomous backfilling operation as illustrated in FIGS. 7A to 7C by,for example, operating the left operation lever 26L in the left turningdirection, or can perform an autonomous backfilling operation (push-offoperation) as illustrated in FIGS. 10A and 10B by operating the leftoperation lever 26L in the arm opening direction.

This configuration can enhance the efficiency of the backfillingoperation compared with the backfilling operation performed in responseto the manual operation of the operation lever. In addition, thisconfiguration can reduce the burden on the operator of the shovel 100for the backfilling operation.

The backfilling operation may include at least one of an operation ofthe excavation attachment AT attached to the upper turning body 3 and aturning operation of the upper turning body 3. Specifically, thebackfilling operation may include at least one of the boom raisingoperation, the boom lowering operation, the arm opening operation, thearm closing operation, the bucket opening operation, the bucket closingoperation, the left turning operation, and the right turning operation,as illustrated in FIGS. 7A to 7C. Alternatively, the backfillingoperation may not include the turning operation, as illustrated in FIGS.10A and 10B. Alternatively, the backfilling operation may not includethe operation of the excavation attachment AT. In addition, thebackfilling operation may include at least one of an operation ofpushing a sediment with the front face of the bucket 6, an operation ofpushing a sediment with the side face SF of the bucket 6, and anoperation of pushing a sediment with the back face BF of the bucket 6.

This configuration can further enhance the efficiency of the backfillingoperation, for example, by enabling the autonomous execution of anappropriate backfilling operation according to a positional relationshipbetween a hole subject to a backfilling work and a sediment pile subjectto the backfilling work.

The controller 30 may be configured to specify a position of a landscapefeature subject to backfilling based on an output of the objectdetection device 70. The landscape feature subject to backfilling maybe, for example, a hole subject to backfilling and a sediment pilesubject to backfilling. For example, the controller 30 may be configuredto specify a position of a landscape feature subject to backfillingbased on an image captured by the imaging device 80. Alternatively, thecontroller 30 may be configured to specify a position of a landscapefeature subject to backfilling based on distance information measured byLIDAR. In this case, the controller 30 may be configured to recognize atleast one of a shape, a depth, and a volume of the hole subject tobackfilling; a shape, a height, and a volume of the sediment pilesubject to backfilling; and a progress of the backfilling work based onan output of the object detection device 70.

The preferred embodiment of the present disclosure has been described indetail. However, the present invention is not limited to the embodimentdescribed above, nor is it limited to what is exemplified below. Theembodiment described above may be subject to various modifications,substitutions, and the like without departing from the scope of thepresent invention In addition, the features described separately may becombined, provided that no technical inconsistencies arise.

For example, according to the embodiment described above, the controller30 is configured to perform the backfilling operation or the likeautonomously or semi-autonomously, thereby reducing the burden on theoperator sitting on a driver's seat inside the cabin 10. However, theautonomous or semi-autonomous operation by the controller 30 may beapplied to a remotely operated shovel. In this case, the controller 30can perform the backfilling operation or the like autonomously orsemi-autonomously, thereby reducing the burden on a remote operatorsitting on a driver's seat inside a remotely controlled room connectedto the shovel 100 via wireless communication.

The controller 30 may also be configured to recognize a positionalrelationship between the shovel 100 and the hole HL based on the outputof the object detection device 70. In this case, the controller 30 mayspecify the position of the hole HL based on the output of a positioningdevice (such as GNSS) mounted on the shovel 100. The controller 30 maybe configured to recognize the positional relationship between theshovel 100 and a sediment pile based on the output of the objectdetection device 70. In this case, the controller 30 may specify theposition of the sediment pile based on the output of the positioningdevice mounted on the shovel 100.

In addition, the controller 30 may be configured to recognize theposition of the hole HL based on the construction plan inputted bycommunication, etc., when the position or shape of the hole subject tothe backfilling operation is set in advance in the construction plan(design data). Similarly, the controller 30 may be configured torecognize the position of the sediment pile based on the constructionplan inputted by communication, etc., when the position or the like ofthe sediment pile subject to the backfilling operation is set in advancein the construction plan (design data). Thus, the controller 30 cancontrol the position of the bucket 6 by comparing the control referencepoint calculated based on the output of the positioning device (GNSS,etc.) or the attitude sensor, etc. mounted on the shovel 100 with theposition (target position) of the sediment pile, the hole HL, or thelike on the construction plan.

It should be understood that the invention is not limited to theabove-described embodiment, but may be modified into various forms onthe basis of the spirit of the invention. Additionally, themodifications are included in the scope of the invention.

What is claimed is:
 1. A shovel comprising: a lower traveling body; anupper turning body turnably mounted on the lower traveling body; and acontrol device disposed in the upper turning body, wherein the controldevice includes a processor, and a memory storing a computer-readableprogram, which when executed, causes the processor to execute a processincluding recognizing a position subject to a backfilling operation, andgenerating a target position relating to the backfilling operation. 2.The shovel according to claim 1, wherein the process includes changingthe target position according to a shape of a sediment at the positionsubject to the backfilling operation.
 3. The shovel according to claim1, wherein the process includes changing an operation content accordingto a height of a sediment at the position subject to the backfillingoperation.
 4. The shovel according to claim 1, wherein the processincludes starting an autonomous backfilling operation by the shovel whena predetermined condition is met, and wherein the predeterminedcondition is a condition in which a predetermined switch has beenoperated, or a condition in which an operation lever has been operatedin a predetermined direction in a predetermined operation mode.
 5. Theshovel according to claim 1, wherein the backfilling operation includesa push-off operation of pushing off a sediment with a bucket withoutlifting the sediment with the bucket, and wherein the push-off operationincludes at least one of a push-off operation of pushing off thesediment with a front face of the bucket, a push-off operation ofpushing off the sediment with a side face of the bucket, and a push-offoperation of pushing off the sediment with a back face of the bucket. 6.The shovel according to claim 1, further comprising: an object detectiondevice attached to the upper turning body, wherein the process includesspecifying a position of a landscape feature subject to the backfillingoperation based on an output of the object detection device.
 7. Theshovel according to claim 1, wherein the process includes performing aleveling operation to level a surface of a sediment when a hole has beenbackfilled.
 8. The shovel according to claim 5, wherein the processincludes performing a leveling operation at a same time as performingthe push-off operation.
 9. The shovel according to claim 1, wherein theprocess includes setting, as a target surface, a virtual surfacecorresponding to a ground formed when a hole is backfilled, generating atarget trajectory along the target surface, and performing a levelingoperation by moving a bucket along the target trajectory.
 10. The shovelaccording to claim 9, wherein a height of the target surface is setbased on a height of the ground around the hole.
 11. The shovelaccording to claim 5, wherein the process includes performing thepush-off operation when an object subject to the backfilling operationis within a predetermined distance range from a hole to be backfilled,and performing the backfilling operation including an excavationoperation when the object subject to the backfilling operation isoutside the predetermined distance range from the hole to be backfilled.12. The shovel according to claim 5, wherein when an object subject tothe backfilling operation is within a predetermined distance range froma hole to be backfilled, the process includes backfilling the objectsubject to the backfilling operation into the hole by a plurality of thepush-off operations s, the plurality of push-off operations being thepush-off operation of pushing off the sediment with the bucket.
 13. Theshovel according to claim 5, wherein the process includes generating atarget trajectory for the push-off operation based on a limit on avolume or a weight of the sediment that can be pushed off by a singlepush-off operation.
 14. The shovel according to claim 5, furthercomprising: an object detection device attached to the upper turningbody, wherein the process includes calculating, based on an output ofthe object detection device, a volume of an object subject to thebackfilling operation within a predetermined distance range from a hole,and a volume of a sediment required to backfill the hole as a requiredvolume, performing the backfilling operation including an excavationoperation when the volume of the object subject to the backfillingoperation is less than the required volume, and performing the push-offoperation when the volume of the object subject to the backfillingoperation is equal to or greater than the required volume.
 15. Theshovel according to claim 1, further comprising: an object detectiondevice attached to the upper turning body, wherein the process includesrecognizing an opening area or a depth of a hole to be backfilled basedon an output of the object detection device, and setting the targetposition based on the opening area or the depth.